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arriving at Saint Louis the next day. This wave was the culmination 

 of six days of constantly increasing warmth, and started the birds be- 

 fore it had reached its maximum. April 25, first arrivals were reported 

 from latitude 41° 22' in Nebraska, and April 26 an increase of summer 



residents, with the first flock of transients, was recorded at Saint Louis 



at both places the day before the maximum of temperature. The night 

 of the maximum (April 27) brought " firsts " to latitude 39° 43' and lati- 

 tude 40° 08' in Illinois. A record was made at latitude 42° 16' in Illi- 

 nois on April 28, but as this was the day after a quite pronounced polar 

 wave it is probable that the birds came the day before with the maxi. 

 mum wave, and had escaped observation. The same remark applies 

 to two records from latitude 40° .47' and 40° 53', April 28 and 29, which 

 probably belong to April 26. The largest wave of the season began 

 at Custer, Mont., April 28. passed Yankton and Saint Paul, and ex- 

 tended down the Mississippi to Saint Louis on the 29th, and reached 

 the Lower Mississippi Valley on the 30th. As in the case of the previ- 

 ous wave, a slight bird movement took place the day before, bringing 

 the first Kingbird to latitude 39° 14' in Missouri, the bulk to latitude 

 39° 43' in Illinois, and flocks of transients to latitude 38° 40' in Missouri. 

 But the next night witnessed the grand movement, which carried the 

 species to latitude 41° 05', 41° 26', 41° 38', 41° 40', and 42° 37' in Iowa, 

 and latitude 39° 19', 41° 36', 41° AC, 41° 58', and 42° 37' in Illinois. 

 Hence it appears that between darkness and daylight there was a solid 

 advance of Kingbirds over 200 miles of territory. Who shall say how 

 many, many thousand were winging their way northward through the 

 silent watches of that night % The notes of May 1 from latitude 41° 14/ 

 in Iowa undoubtedly also belong to this wave. The night of May 1 was 

 cold throughout the northern half of the Mississippi Valley, and was 

 followed two days later by a warmer period, which marked another ad- 

 vance of Kingbirds to latitude 43° 06'. In this wave there was no such 

 uniformity of movement as in the preceding. Indeed, out of the seven 

 uotes which have been apportioned to it, only two hit the maximum 

 exactly; but considering them all to pertain to this wave, the advance 

 is found to be at latitude 43° and 43° 06' in Wisconsin, and latitude 43° 

 43' in Minnesota, with the bulk at latitude 39° 12' in Illinois and lati- 

 tude 41° 14' in Iowa. The culmination of the next wive extended from 

 May 8 in the northwest to May 10 in the southeast. During the five 

 days of preparation for this wave there were no notes. On the day 

 preceding, the bulk arrived at latitude 42° 56' in Dakota ; the first at 

 latitude 44° 22' in Wisconsin and at latitude 45° in Minnesota, while 

 on the day of the maximum "firsts" were recorded at latitude 43° 43' 

 and 44° 30' in Wisconsin, latitude 44° 32' in Minnesota, latitude 38° 

 55' in Kansas, and latitude 47° 08' in Dakota, with new arrivals of bulk 

 at latitude 43° 06' in Wisconsin and 41° 36' in Iowa. Thus there was 

 nearly as much real advance during these nights as during the lasd 

 wave of April, the difference being that the April wave spread over all 



